Expansion-bit.



w. B. SWAN EXPANSION BIT.

APPLIUATION'PILBDMlm-1, 190s.

W/TNESSES A ATTORNEY' WILLIAM B. -SWAN, CE SEYMOUR, CONNECTICUT.

ExPANsloN-Blr.

Specification of Letters Patent.

Patented Oct. 30, 1906.

Application iiled March 14, 1906. Serial N o. 305.999.

To wwhom t may concern.-

Be it known that I, WILLIAM B. SWAN, a citizen of the United States, residing at Seymour, county of New Haven, State of Connecticut, have invented a new and useful Expansion-Bit, of which the following is a specication.

This invention relates of expansion-bits-that is, bits provided with expansion-cutters for the purpose of boring holes of different diameters, but adapted to work'equally well as ordinary bits Without the expansion-cutters `and my invention to the construction has for its object to simplify, cheapen, and to prove their mode I ing pinion detached,

I the retaining-block, both of generally improve the construction of this class of bits and to greatly simplify and imof operation in use.

With these and other objects in viewI have devised the novel expansion-bit, of

ywhich the following description, in connection with the accompanying drawings, is a speciiication, reference dicate the several parts.

Figure 1 is an elevation of my novel expansion-bit, showing the manner in which the expansion-cutter operates; Fig. 2, an elevation as seen from the right in Fig. 1 g Fig. 3, a vertical section, on an enlarged scale, on the line 3 3 in Fig. 1 looking in the direction of the arrow; Fig. 4, an elevation oi the expandand Fig. 5 is an elevation ofthe retaining-block detached.

l0 denotes the shank, 11 the tang, 12 the body, 13 the gimlet, 14the cutter, and 15 the lip, of a bit, auger, or other boring-tool.

So far as my present invention is concerned it is immaterial to what type of bit or auger it is applied. In the present instance I have illustrated myinvention as applied to a singlegrooved bit, the groove being indicated by 16.

17 denotes the expansion-cutter, and 18 which lie in a recess 19 at the lower end of the body. This recess is shown as undercut at both its upper and lower edges, as at 20 and 21, and as extending in a direction slightly obli ue to a line at right angles to the axis ofthe it.

4 The expansion-cutter is provided with a cutting edge 23 and a lip 24. The back of the expansion-cutter is undercut to correspond with undercut 21 in the recess in thel body. At the top of the expansion-cutter is a forwardly-inclined rack 25. The upper l l f characters being used to inthe locking-screw is edge of the retaining-block is beveled to engage undercut 20 in-the recess in the body, and its lower edge is beveled to overhang the rack upon the extension-cutter. 27 denotes a socket in the retaining-block, which is provided with an opening 28 in its lower side and which receives an expanding pinion 29. This pinion, the retaining-block, and the body are provided with corresponding screwholes to receive a locking-screw 30. The pinion is provided with a cut 31, leading from its outer periphery into the central opening, whereby it is made expansible, and the upper edge of the opening is beveled, as yat 32, to correspond with a taper 33 on the lockingscrew, by which the pinion is expanded when turned in.

The operation will be readily understood from the drawings. In the present instance I have illustrated a seven-eighths bit in the drawings. Should it be required to bore a hole of greater diameter than seven-eighths of an inch, an expansion-cutter would be used. To insert or remove an expansioncutter, it is not necessary to remove the locking-screw, but merely to loosen it. lAs soon as the locking-screw is turned backward the pinion will contract, leaving' the expansioncutter free to be moved in either direction'or' .thereon engages the bevel of the pinion and expands the pinion, forcing the teeth of the pinion into engagement with the rack upon the expansion-cutter and also with the periphery of the socket in the retainin -block, thereby locking the block, cutter, an pinion rigidly in place.

I-Iaving thus described my invention, I claim- 1. In a bit, the-combination with an expansion-cutter provided with a rack, of a retaining# lockprovided with a socket, an expandin pinion in said socket which engages the rac and a tapering screw whereby the pinion isl expandedI to lock the expansioncutter in position after adjustment.

2. In a bit, the combination with an eX- pansion-cutter provided with a rack, of a re- IOS taining-block providedwith a socket, a pn- In testimony whereof I affix iny Signature ion naic soket having si beveled he alild in p'es'ence of two witnesses. a out om t e outer eri ery inwar to t e hole and a screw pasgingpthljon'ghthe pinion l WILLIAM B' SWAN' 5 and the retaining-block and having a taper Witnesses:

engaging the pinion whereby the latter is eX- fl HART CULVER, panded and the parts are looked in place. A. AUGUSTA SWAN. 

